Effects of Electric Field and Temperature on Spontaneous Polarization in the Vicinity of Isotropic to Antiferroelectric B2 Phase Transition in a Banana-Shaped Mesogen 12OSOR

Using a phenomenological free-energy density expansion, in this work, we have studied the effects of temperature and electric field on the spontaneous polarization of antiferroelectric B-2 phase in the vicinity of I-B-2 phase transition in a bent-core mesogen 12OSOR. The free-energy density of the system is written in terms of tensor orientational order parameter Q(ij), scalar smectic order parameters psi(1) and psi(2), the vector polarization order parameter P-a and the resulting couplings between these order parameters. Using the Landau coefficients, as determined from the experimental values of relevant quantities, we evaluate the temperature and electric field variations of spontaneous polarization and found that the theoretical results agree well with the experimental data of bent core achiral thioester mesogen 12OSOR.